Good Mortar 



273 



back side of the wall to near the face, if the 

 bond is made good. No stone should reach 

 entirely through the wall, since in cold weather 

 the frost will follow through such stones from 

 face to rear. 



There is no economy in using mortar which 

 is poorly mixed or that which contains too 

 much sand and too little lime or cement. If 

 the lime or cement, that 

 is, the binding mate- 

 rial, does not come into 

 immediate contact with 

 every particle of sand, 

 then the mortar will be 

 weak. If not enough of 

 the cement or lime is 

 used, the bond will also 

 be weak. For stone 

 walls not more than four 

 parts of sand to one of 

 cement or lime should 

 be used. If the sand be 

 sharp and clean a much 

 stronger mortar is se- 

 cured than when it is 

 composed in part of rotten sand mixed with vege- 

 table matter. If the materials are good and they 

 are mixed in the right proportion, still good mor- 

 tar will not be secured unless they be thoroughly 





\S^'-^ '-i.>ii«-l 



Fig. 103. 

 Poorly and properly bonded. 



